Today a severe event happened at QHD site. NO INJURIED PERSONS, but could be in other circumstances with multiple fatalities. During closure process when UW mold was raised at the vertical position mold has separated from turning device suddenly and slipped down toward DW mold.Investigation started in order to understand the cause(s), waiting the conclusion, many sites could be impacted with the issue.FOR ALL SITES:• STOP the WORK on the closing activities and realize the 3 next actions. • Please Organize a visual check of your installations, in order to detect , cracks , default, … • Reinforce the last minutes check on the mold before to do the closing operations.• Reorganize the work with employees in order to not authorized the access to the left and right of the mold with a minimum distance of 10 meters at Left and Right.